The Stovebolt Site Forums The Parking Lot Tons 'o Fun 19.5" P30 wheels don't fit 54 1 ton dually :(

I bought some of the P30 wheels for my 1 ton dually. Hub bore fits perfect, but the lug holes are 5/8" I think (larger than the 1/2" lugs I have now). I decided to go ahead and put the front ones on anyway to see how the truck handled, and they run great without any give on hard braking. Huge difference in the way the truck feels with modern radials.

The back inner wheels won't fit over the drums though. I got the wheels off of a 1991 P30 with the cummins 4BT and I think either the 14 bolt GM rear, or the Dana 70. I don't know why the rear inners are that much different according to the P30 swap article by Grigg. Who knows, maybe the P30 was newer than what the guy said and it had the wrong wheels for my needs.

Since the 3-piece rear tires were totally shot, I went ahead and put the P30 wheels on the back outers (left the inners off). This should work okay until I get the GM14 bolt axle swapped out, then all of the wheels should fit.

I should be okay running just the outers on the back as long as I don't load the truck down, right? I took it for a test drive and was pretty hard on the truck and it felt wonderful with all new radials on it.

Hopefully I can get by like this until the rear axle swap.

Any advice is welcomed.
Thanks,
Skybum

Some of the original brake drums are really big, and don't fit modern wheels as you found. This is why test fitting any wheel before buying is a good idea. This is a known problem with 19.5" wheels on the 1.5 and 2 ton trucks too, some fit but many don't.
I don't think you'll find any other 19.5" wheels that do fit, they are pretty standard.

However, the 14 bolt axle swap I think is the best solution and an improvement in gear choices, brakes, and wheels, so all around a better deal.

Running just the outers with no load in the bed should get you by until the axle swap.

The larger stud hole in the new wheels should be solvable with the proper lug nuts.
I assume you're using the clamp rings from the P30 too? Take one in to the parts place and ask for a 1/2" lug nut big enough to fit the chamfer.

Grigg

Duals in the rear add more stability than practical load rating. Unless you're overloading the truck I doubt you'll have any trouble running just the outers on the rear.

Running only one dual wheel loads the wheel bearings differently, most of the load is on one bearing and not shared evenly by both.
With both wheels on the hub the center of the pair of tires is close to the center between the two wheel bearings. With only one tire the center of that tire is outside the pair of wheel bearings.

I expect it'll work, but I would not overload it, or get close to the rated load.

If you run single wheels (from a single wheel truck) in the rear you would be OK as Steve points out, and no bearing issues, just tire and wheel load rating to consider.

Grigg

Thanks for the suggestions guys. For now I really only need the truck operational so that I can move it from the driveway to the street and vice versa to get other equipment moved around.

I'm going to shoot for the axle swap in the near future. Hopefully the P30 short axle will work okay, and that getting the driveline modified to fit won't take too long.

I will have to say though that the radials on the front make a hell of a lot of difference in handling. No more sudden wandering or jerking of the steering. I'm loving it. Can't wait to get the rear axle in, once I acquire one.

Thanks for the good info fellas.

Check the measurements between tires and the distance outside springs, I think it'll be really close.

Read through the 14 bolt rear axle thread. https://www.stovebolt.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=599879#Post599879
It's about a cab and Chassis axle for a 1 ton pickup, but my dimensions and findings on the spring pads will be helpfull on your dual wheel truck.

I think you'll want an axle wider than a Cab & Chassis 14 bolt.

Grigg

Take a hard look at the wheels you took off. It may have been bent wheels instead of bias ply tires.

While bad tires can cause poor handling in my experience its usually been the wheels that were actually the problem.

Grigg (and OldSub),
After reading through your SRW 14 bolt post about 5 times, I couldn't help but wonder about doing a SRW 14 bolt swap, but running my duals on the SRW hub. My understanding is that the housings on the C&C dually and the SRW dually are the same distance, only WMS-WMS difference being in the mating surface placement on the hub (assuming that after reading your pirate 4x4 link). I know that there would be a small moment on the hub running duals on the SRW hub, but the newer axles and bearings should be rated for quite a bit higher than I'll ever load them. GVWR for the 3800 is only 8800 lbs I think.

What are your thoughts on that idea? I'd be able to keep the duals tucked in and also gain tire clearance to the springs (wouldn't have to go all the way to a full width truck rear end).

I have what appears to be an early SRW 14-bolt under my '54 1-ton.

This picture shows how it fits. Since the WMS to WMS is wider than stock I see no problems with tire fit on the inside.

Its only a little wider than stock so you will not become too wide if you have a couple inches on each side to spare.

I've not tried duals on this axle, but since the brakes are smaller than the 14 inch originals I would expect even 16 inch wheels to work. You might need longer studs.

Since the center of the wheels is in almost the same location whether running duals or singles I don't think there is an impact on bearings to worry about. However the weight is probably more than double which has an impact on braking efficiency (important) and un-sprung weight (probably not important).

Unless you plan to run heavy loads I don't think the brake issue is a big deal either, but it is worth being aware of.

Just my .02 I have seen the outer wheel bolt area break out, when the inner wheel had gone flat with no load. but there could have other reasons it went bad??

Could the lug nuts have come loose? Maybe even causing the flat?

I ask because things usually only break along lines of flexing or movement and unless the lug nuts came loose I don't see a flat tire causing that.

SUB I have no real clues,just saw it happen

Would front and rear disk brakes solve that problem? Surely they'd be better than the old originals.

I'm just trying everything to avoid the full width dual rear end.

Thanks.

Double and triple check the measurements and if the tires and wheels fit both over the brakes and outside the springs.
A rear disc brake conversion might solve the wheels over brake drum problem if there is one.

Grigg

I wouldn't do rear disk without also doing front. Fortunately disk on the DRW front has been done enough that you can follow someone else's approach rather than start from scratch figuring it out.

I'm not sure you have a problem if you can find the same rear I've got under mine. Its enough wider than stock that spring clearance should not be an issue.

The only question is brake fit, and while a 16 inch dually wheel might not go over the brakes the 19.5 certainly would.

I'd suggest some measuring rather than let my confidence replace reality, but since you have the 19.5 wheels you can measure them before going shopping for a rear.

Well the rear end (C&C) that my wheels came off of is still available and I intend to go get some measurements as soon as I can break away from home. It's about 80 miles away and between working a lot of OT at work and the demands of a family I've been quite busy.

Seems like sometimes time is a more precious commodity than money. Hopefully next weekend I can sneak away and go measure it.
Thanks for all the advice.

On a side note, I took a load of brush and junk to the big dump we have here. Two separate times guys asked my if I was interested in selling my truck. Made me feel proud of the ol'rusty girl.

I used to tell me people like that I wanted $22,000 for my Suburban. But even with original patina and an excess of rust the responses got too serious so now I just laugh.

I'm seeing several single rear wheel 14 bolt rear ends for sale, but I think they're mostly out of 3/4 ton pickups. What's going to be the difference between a 3/4 ton and 1 ton 14 bolt? Are the brakes on a 3/4 ton smaller than the 1-ton, that being the only difference?

You want a full float not a semi float.

The full-float will have a big hub sticking out the center and 8-lugs. The semi-float will not have a hub sticking through the wheel and usually (perhaps always) is only 6-lug.

The semi-float is common in 1/2-ton and light duty 3/4-ton trucks. The full-float is usually under heavy duty 3/4-ton trucks and 1-tons that don't have a Dana.

Make sure you can tell a Dana from a 14-bolt though a Dana 70-HD the right width wouldn't be a bad thing.